Implantable bone plate system and related method for spinal repair

ABSTRACT

A system for performing surgical repair of the spine includes a distractor and a permanently implanted bone plate system. A surgical repair methodology is also disclosed that employs an implanted bone plate system with a substantially void internal volume which is attached to adjacent vertebrae subsequent to the distraction and/or adjustment of curvature of the vertebrae and prior to the excision of disc and/or end plate tissue through the bone plate. The device further facilitates the subsequent delivery of an interbody repair device for the purpose of either fusion or dynamic stabilization, such as by disc arthroplasty. The plate may be permanently implanted, such as when a fusion between the attached vertebral bodies is desired, but it need not be permanently implanted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 11/855,124(titled, “Implantable Bone Plate System and Related Method for SpinalRepair”) filed Sep. 13, 2007, which claims priority to U.S. ProvisionalPatent Application Ser. No. 60/954,511 (titled “Implantable Bone PlateSystem and Related Method for Spinal Repair”) filed Aug. 7, 2007.

The present invention relates to a system for performing surgical repairof the spine, such as for but not limited to the delivery of aninterbody repair device for the purpose of either fusion or dynamicstabilization.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND OF THE INVENTION

It is current practice in spinal surgery to use bone fixation devices toimprove the mechanical stability of the spinal column and to promote theproper healing of injured, damaged or diseased spinal structures.Typically, corrective surgery entails the removal of damaged or diseasedtissue, a decompression of one or more neural elements, followed by theinsertion of an intervertebral implant for the purposes of a fusion ordisc arthroplasty. In cases where spinal fusion is the desired surgicaloutcome, the final step is often to apply a bone plate in order toimmobilize adjacent vertebral bones to expedite osteogenesis across saidvertebral segments.

Most current surgical techniques require that damaged vertebral tissuebe placed under rigid axial distraction throughout much of theprocedure. This allows for greater ease in the removal of tissue,provides a larger working space for instrument maneuverability, enhancesthe surgeon's visibility and assists with the fit of the interbodyimplant once the distractor apparatus is removed. Conventionaldistraction of the spine typically employs the use of temporary“distractor pins” placed directly into the bone tissue adjacent to thedisc space to be repaired, which are subsequently induced to moveaxially by the attachment and adjustment of a secondary tool. Analternative method employs the use of a ratcheting spreader device whichis inserted directly into the vertebral interspace and is adjustedthereafter to achieve desired distraction. These distraction methodsoffer an imprecise means to restore preferred vertebral alignment, addseveral steps, require more time to install and remove, increase therisk for entwining of surrounding vascular structures or peripheralnerves and can present significant physical impediments and technicalchallenges to the surgeon. Additionally, because the distractor deviceremains temporarily inserted during the decompression and fusionportions of the procedure, the surgeon must essentially work around theobtrusive projecting devices while completing the majority of thesurgery.

It is also known that current distraction methods, while generally notdesigned or intended for this purpose, are often employed to adjust ormaintain the angular alignment of adjacent vertebra in an attempt torestore normal lordotic curvature. The outcomes are varied, the degreeof distraction and the angular correction produced by currentdistraction methods are often imprecise, require substantial subjectiveassessment by the surgeon and can vary significantly from patient topatient. Further, excessive distraction can result in a negativesurgical outcome which can result in nerve damage or on-going postsurgical pain for the patient.

There is a high degree of dimensional variability in the resultingintervertebral volume after distraction has been achieved using thesedevices. As a result, the surgeon must often make “trial and error”assessments as to the size and shape of the interbody implant to beinserted and may be required to customize the implant intraoperativelyprior to final insertion.

In the conventional method, once the implant has been inserted, thedistractor device is removed and the vertebrae can be secured by theattachment of a bone plate. Such bone plates, including a plurality ofbone screws, are applied near the completion of the procedure to providevertebral fixation and prohibit undesirable migration of theintervertebral implant.

Several design constructs have already been proposed in which a deviceis applied to adjacent vertebrae at the start of a procedure, prior totissue removal, for the purposes of achieving and maintaining preferredvertebral alignment while serving also to constrain tissue removalthroughout the procedure. The disclosed or published art in this methodcan generally be categorized into two broad categories: removabledevices and permanently implantable devices.

The removable devices differ from the present proposed invention in thatthe devices used to maintain preferred vertebral alignment are temporaryinserts and are subsequently removed after tissue removal so that arepair device may be delivered thereafter. The prior art which disclosespermanently implantable devices differs in that the devices functionsolely to maintain preferred vertebral alignment and are not part of acomprehensive system and related method to precisely control andpermanently maintain the preferred spatial relationship of adjacentvertebral members for controlled tissue removal and delivery of a repairdevice.

Removable Devices

U.S. Pat. No. 7,153,304 entitled Instrument System for Preparing a DiscSpace Between Adjacent Vertebral Bodies to Receive a Repair Device,issued Dec. 26, 2006 to Robie et al., discloses a removable instrumentsystem for preparing a disc space between adjacent vertebral bodiesusing a series of distractors that restore natural lordosis before atemporary template is attached for vertebral immobilization and tofunction as a guide for an insertable reamer meant for tissue removal.

U.S. Pat. No. 7,083,623 to Michelson, entitled Milling Instrumentationand Method for Preparing a Space Between Adjacent Vertebral Bodies,issued Aug. 1, 2006, discloses a removable milling device and method forpreparing a space between adjacent vertebral bodies which essentiallymaintains preferred vertebral alignment while functioning as a saw guideto control bone and soft tissue removal.

US Pat. App. 2005/0043740 to Haid, entitled Technique andInstrumentation for Preparation of Vertebral Members, published Feb. 24,2005, discloses a removable instrumentation set and technique forpreparation of vertebral members utilizing a docking ring which istemporarily applied to the anterior spine to maintain preferredvertebral alignment and to function as a docking plate for anarticulating bone removal device.

U.S. Pat. No. 7,033,362 to McGahan, entitled Instruments and Techniquesfor Disc Space Preparation, issued Apr. 25, 2006, discloses a removableinstrumentation set and method for disc space preparation whereby anintervertebral device is temporarily inserted for the purpose ofconstraining tissue removal and guiding the position of anintervertebral repair device.

US Pat. App. 2003/0236526 to Van Hoeck, entitled Adjustable SurgicalGuide and Method of Treating Vertebral Members, published Dec. 25, 2003,discloses a removable surgical guide and method with adjustablefunctionality for the preparation of adjacent vertebra.

US Pat. App. No. 2006/0247654 to Berry, entitled Instruments andTechniques for Spinal Disc Space Preparation, published Nov. 2, 2006,discloses a removable milling instrument assembly for vertebral endplatepreparation which constrains a cutting path obliquely oriented to theaxis of the vertebra.

Permanently Implanted Devices

US Pat. App. 2004/0097925 to Boehm, entitled Cervical Spine StabilizingSystem and Method, published May 20, 2004, discloses a permanentlyimplantable spine stabilizing system and method whereby a plateconfigured to be positively centered along the midline is placed toretain adjacent vertebra in a desired spatial relationship duringdiscectomy and fusion procedures. The disclosed invention uses a seriesof temporary implants and removable drill templates in an attempt toassure the alignment of the implanted device along the midline of thespinal column. This alignment is typically not considered to besignificant in determined the clinical outcome of the procedure and isfurther considered impractical for the purposes of performing repairprocedures on multiple adjacent disk spaces due to the normal scolioticcurvature of the spine.

US Pat. App. 2005/0149026 to Butler et al., entitled Static and DynamicCervical Plate Constructs, published Jul. 7, 2005, describes animplanted cervical bone plate having a graft window located between thebone screw holes for the purposes of providing visualization and accessto an intervertebral implant. The device described is applied after theintervertebral space has been repaired and after the implant has beenpositioned. The specification states specifically that an appropriately“sized dynamic plate is placed over the inserted bone implant”;thereafter the bone plate is located with respect to the implant byviewing the implant through the graft window and secured in place usingbone screws.

Accordingly, it is apparent that there remains a need for and advantageto a permanently implantable spinal repair system and related methodwhereby the final preferred vertebral alignment and fixation occursprior to the surgical removal of damaged tissue, without the use oftemporary implants or fasteners and where the surgical procedures can beperformed there-through in the minimum amount of time with the minimumnumber of entries into the surgical field. It is further apparent thatthere is a need for a system wherein subsequent recovery procedures canbe performed with minimal effort should implantation fail or shouldsubsequent surgery be required.

SUMMARY OF THE PRESENT INVENTION

The invention relates generally to systems and methods for establishingand securing adjacent vertebrae in a defined spacial relationship priorto the excision and repair of damaged tissue. In one embodiment, thesystem includes at least one distraction device, at least oneimplantable vertebral frame, at least one interbody repair implant, andat least one retention member. In this embodiment, the distractiondevice is configured for temporary placement between adjacent vertebraefor achieving a desired spatial relationship between the vertebrae. Inthis embodiment, the implantable vertebral frame is configured to spanbetween the adjacent vertebrae, the frame being configured to attach toeach of the adjacent vertebra while the distraction device is in placeto postoperatively maintain the desired spatial relationship between thevertebrae after the distraction device is removed, the frame also havingat least one internal operating aperture there-through for providingaccess to at least one intervertebral disk space. In this embodiment,the interbody repair implant is sized in relationship to the aperture ofthe frame to fit there-through and into the intervertebral space. Andfinally, in this embodiment, the retention member is attachable to theframe to cover at least a portion of the aperture.

In various embodiments of the above summarized system, the frame mayassume various forms and include various features that will now besummarized. In some embodiments of the system, the frame may beconfigured to span between and remain postoperatively attached to atleast three adjacent vertebrae. In some embodiments of the system, theframe may include external walls having integrally manufacturedretractor blade engaging features. In some embodiments of the system,the frame may have a plurality of through holes to facilitate attachmentof the frame to adjacent vertebrae by means of bone screws. In some ofthese particular embodiments, the holes may be a combination ofelongated slots and circular holes to accommodate the insertion of bonescrews there-through into vertebral bone tissue. In some embodiments ofthe system, the frame may have a plurality of protrusions to facilitateattachment of the frame to the adjacent vertebrae by means ofimpingement into the bone tissue of the adjacent vertebrae.

Further, in some embodiments of the system, the frame may have one ormore receiving elements to accept a locking member for securing theretention member. In various of these particular embodiments, thelocking member may be any of a threaded screw device, a snap lockdevice, or a cam lock device, and further in some of these particularembodiments, the one or more receiving elements for the retention membermay accommodate the temporary location of at least one tissue retractorpin.

Still further, in some embodiments of the system, the frame may beconfigured to receive bone screws there-through to attach the frame tothe vertebrae, the retention member being adapted to cover the bonescrews when the member is attached to the frame to prevent back-out ofthe screws.

In some embodiments of the system, the retention member may beconfigured to retain the interbody implant in its surgically establishedposition.

According to an aspect of the invention, a vertebral implant may beprovided. Embodiments of the implant are configured to rigidlyinterconnect at least two vertebrae, the implant being manufactured froma generally rigid material having thereon contact surfaces for engagingon vertebral bone material, the contact surfaces including abiocompatible, compressible, polymeric material. In some of theseembodiments, the generally rigid material may also include abiocompatible metallic material.

In another aspect of the invention, various embodiments of methods areprovided for applying the system and/or the vertebral implant, assummarized above. In one method of applying the system, the adjacentvertebrae are distracted and spacially oriented with the distractiondevice, the vertebral frame is secured to the adjacent vertebrae, thedamaged tissue is excised through the operating aperture in thevertebral frame, the vertebral interspace is prepared to receive therepair implant, said implant being placed through the operating apertureinto said prepared interspace, and the retention member is theninstalled onto the vertebral frame.

Another embodiment of a method for applying the system is also provided.In this embodiment, the vertebral frame is attached to one or morevertebrae, the vertebrae are then distracted and spacially oriented byoperating through the operating aperture in the vertebral frame, thevertebral frame is secured to each adjacent vertebrae, the damagedtissue is excised through the operating aperture in the vertebral frame,the vertebral interspace is prepared through the operating aperture toreceive the repair implant, the interbody implant is inserted throughthe operating aperture into the prepared interspace and the retentionmember is installed onto the vertebral frame.

In another aspect of the invention, a method for treating a portion of aspinal column is provided. The method includes distracting and spaciallyorienting adjacent vertebral bodies of the spinal column, securing avertebral frame to the adjacent vertebral bodies, the vertebral framehaving at least one operating aperture there-through, preparing avertebral interspace to receive an interbody implant, inserting theinterbody implant through the operating aperture and into the preparedinterspace, and maintaining the vertebral frame in place on thevertebral bodies postoperatively.

In some embodiments of this method for treating a portion of a spinalcolumn, the distracting step is performed using a distraction deviceplaced between the vertebral bodies, and the distraction device isremoved from between the vertebral bodies through the operating aperturein the vertebral frame after the vertebral frame is secured to thevertebral bodies. In some of these methods for treating a portion of thespinal column, the method may further include the step of excisingdamaged tissue through the operating aperture in the vertebral frame.

In another embodiment, the method may further include the step ofinstalling a retention member onto the vertebral frame after insertingthe interbody implant. In still other embodiments, the step of preparinga vertebral interspace to receive an interbody implant may be performedthrough the operating aperture of the vertebral frame.

In some embodiments of the method for treating a portion of the spinalcolumn, the vertebral frame may have particular features or aspects.Thus, in some embodiments, the vertebral frame may be attached to atleast one of the vertebral bodies before the distraction step, thedistraction step being performed through the operating aperture in thevertebral frame. In other embodiments, the vertebral frame may besecured to more than two adjacent vertebral bodies. In still otherembodiments, the vertebral frame may be maintained in place permanently,generally from the time it is first secured to the vertebral bodies.

According to some aspects of the present invention, a means and methodto precisely control and permanently maintain the preferred spatialrelationship of adjacent vertebral members prior to the surgical removalof damaged tissue may be provided.

According to some aspects of the invention, a means may be providedwhereby preferred spatial relationship of adjacent vertebra can beachieved and permanently maintained using conventional vertebraldistraction methods or in conjunction with a novel intervertebraldistractor apparatus disclosed separately in the co-pending patentapplication Ser. No. 60/954,507 titled “Device and Method for VariablyAdjusting Intervertebral Distraction and Lordosis” filed on Aug. 7,2007.

According to some aspects of the invention, the surgical removal ofdamaged tissue may be constrained in order to minimize the risk ofdamage to the adjacent tissue.

According to some aspects of the invention, the preferred spatialrelationship of adjacent vertebral members may be precisely controlledand permanently maintained with a device having a low profile, allowingthe surgeon to work in an unrestricted manner, within, around, above andbelow the device.

According to some aspects of the invention, the preferred spatialrelationship of adjacent vertebral members may be precisely controlledand permanently maintained for the insertion of a spinal repair device.

According to some aspects of the invention, the insertion of a spinalrepair device may be spatially controlled.

According to some aspects of the invention, a locking member may beaccommodated to prevent undesirable migration of the spinal repairdevice and bone screws.

According to some aspects of the invention, the method and device may beutilized across one or multiple vertebral segments.

According to some aspects of the invention, a permanent rigid internalfixation may be provided across one or multiple vertebral segments.

In one particular embodiment, a permanent semi-rigid fixation isprovided across one or multiple vertebral segments.

In one particular embodiment, a retractor apparatus is accommodated byproviding integrally manufactured receiving and engaging means for thetissue control blades of said retractor.

In one particular embodiment, removable templates which locate andconstrain the surgical removal of tissue to the desired vertebral areaare accommodated.

In one particular embodiment the vertebral fixation element in thesystem is manufactured using two biocompatible materials, the structuralcomponent being manufactured from a high modulus rigid material such asTitanium, Stainless steel or other metal and having therein contactelements for engaging on the vertebral tissue, said contact pads beingmanufactured from a bio-compatible compliant material such aspolyethylene or a silicone. These contact pads are intended to beplastically deformed under compressive loads and to be compressed anddeformed by the insertion of the bone screws in order to act as dampingelements to absorb vibration during bone tissue removal and consequentlyto minimize the risk of associated screw dislocation. These pads furtherincrease the initial friction between the vertebral fixing element andthe vertebrae thereby reducing premature dynamic compression of thedistracted vertebrae. Finally, the compliant elements act as shockabsorbers during patient healing and promote osteogenesis within theimplanted repair device.

In one particular embodiment, the inventive device may be coupled with astereotactic navigational system for preferred device positioning and toconstrain the surgical removal of tissue.

DESCRIPTION OF INVENTION

The invention described herein includes a system and surgical method foruse in surgical spinal repair or reconstruction procedures wherebypreferred and final vertebral axial and angular positioning and fixationoccurs prior to the cutting and removal of the tissue.

In one embodiment, the system can generally be described as acombination of:

-   -   1) An intervertebral distraction device placed temporarily        between adjacent vertebrae for purposes of achieving a desired        spatial relationship between adjacent vertebrae.    -   2) A vertebral plate.    -   3) A locking and retention member engaging with said vertebral        plate.    -   4) An implantable interbody repair device.    -   5) Bone screws.    -   6) The vertebral plate having through holes for the purposes of        accommodating attachment to the vertebrae using the bone screws.    -   7) Said vertebral plate having a generally open interior volume        through which the removal of damaged tissue is performed.    -   8) Said vertebral plate having a generally open interior volume        which constrains the insertion and prevents migration of an        intervertebral repair device.    -   9) Said vertebral plate having accommodation means for attaching        the locking and retention member for retention of the implanted        repair device and the bone screws.    -   10) One embodiment of the surgical method may be generally        described as the sequence of spacially orienting adjacent        vertebrae, locking said vertebrae in their prescribed relative        positions using the vertebral plate and bone screws, preparing        and repairing the intervertebral space through the operating        window in the installed vertebral plate and securing the implant        in place by securing a locking member to the vertebral plate.    -   11) An alternate surgical method may be generally described as        the sequence of attaching the vertebral plate to one of the        adjacent vertebrae, spacially orienting the adjacent vertebrae        through the operating window in the vertebral plate, locking        said vertebrae in their prescribed relative positions using the        vertebral plate and bone screws, preparing and repairing the        intervertebral space through the operating window in the        installed vertebral plate and securing the implant in place by        securing a locking member to the vertebral plate.    -   12) In an alternate surgical method, the vertebrae are partially        distracted and held in this position by the insertion of bone        screws through slots in the vertebral plate. In this instance        the final distraction is achieved by the forcible insertion of        an interbody repair device which has a cranio-caudal dimension        that is larger than the dimension of the receiving        intervertebral space. The differences in the two dimensions        results in a further, final distraction of the adjacent        vertebrae. This final movement of the vertebrae is accommodated        by the movement of the screws within the slots in the vertebral        plate.

In an anticipated procedure a conventional intervertebral distractorapparatus is manually inserted into or between the vertebrae resultingin axial distraction of the vertebrae. In the case of a standard wedgestyle distractor the degree of distraction results from a combination ofthe included angle and the depth to which it is inserted between thevertebrae. In the case of a distractor pin system the distractionresults from the manipulation of a secondarily applied axial adjustmentdevice.

In a further embodiment the included angle of the distractor device isvariably adjustable by the surgeon after insertion between thevertebrae, this adjustment being achieved mechanically by means of ascrew adjustment or the use of another adjusting tool. Such a distractordevice is disclosed in the co-pending application Ser. No. 60/954,507titled “Device and Method for Variably Adjusting IntervertebralDistraction and Lordosis” filed on Aug. 7, 2007.

In a further embodiment the distractor apparatus can be mated with astereotactic navigational device to establish, monitor and control thepositioning of the device relative to the adjacent vertebra.

After distraction and lordotic adjustment has been achieved the spinalbridge is located on the vertebrae relative to the distractor device andattached to the adjacent vertebra by at least two bone screws, securingthe vertebrae in their prescribed positions.

If intervertebral distractor devices have been employed they areremoved, exposing a predefined accessible and constrained operatingfield allowing the controlled cutting and removal of tissue to occur.

In a further embodiment the vertebral plate can accommodate insertablecontrol templates which can be placed within it by the surgeon tofurther assist precise tissue removal.

In a further embodiment the vertebral plate can serve as a mounting basefor the attachment of soft tissue retractors, further aiding the surgeonby assuring an un-impeded surgical field.

In a further embodiment the vertebral plate can be removed after theplacement of a disc arthroplasty device.

The intervertebral repair device may be generally wedge shaped, it mayhave an initial radius or taper for engagement with the adjacentvertebrae or it may be conically or cylindrically shaped.

Further, this device may have surface contours thereon which areintended to increase the surface area of contact between said surfacesand the exposed cancellous bone tissue and to increase the intimatecompressive engagement with said cancellous tissue so as to induce andencourage osteogenesis therein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows the typical sequence of steps in a current surgicalprocedure.

FIG. 1 b shows the sequence of one embodiment of the inventive methodherein.

FIG. 2 a is an anterolateral isometric view of a single levelimplantable bone plate.

FIG. 2 b is a posterolateral isometric view of a single levelimplantable bone plate.

FIG. 3 a is an anterior isometric view of a multi-level implantable boneplate.

FIG. 3 b is a lateral isometric view of a multi-level implantable boneplate.

FIG. 4 is an oblique perspective view of a multi-level bone plate.

FIG. 5 illustrates a retention member relative to the vertebral frame.

FIG. 6 depicts a retention member in an installed position on thevertebral frame.

FIG. 7 is an anterior (surgical) view of a vertebral frame in itsinstalled position on adjacent vertebrae.

FIG. 8 is an anterolateral perspective view of the vertebral frame inits installed position on adjacent vertebrae.

FIGS. 9 and 10 depict a retention member in-situ after installation ontothe vertebral plate.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a describes the typical operational sequence currently employed,wherein vertebrae are distracted, tissue is excised, an implant inplaced between adjacent vertebrae and a bone plate is attached. FIG. 1 bdescribes the preferred operational sequence associated with thisinvention, wherein vertebrae are distracted and placed in theirpreferred relative angular positions and a vertebral frame is attachedto adjacent vertebrae using bone screws to maintain the prescribedspatial relationship during the subsequent steps. In an alternativesequence, the vertebral frame may be attached to adjacent vertebraeprior to distraction and preferred positioning. Thereafter tissue isexcised though the aperture in the frame, the implant is insertedthrough said aperture. A retaining member may be attached to saidvertebral frame to maintain the position of the implanted insert and toprevent back-out of the bone screws.

FIGS. 2 a and 2 b depict a single level vertebral frame, intended tosecure two adjacent vertebrae. The device has surfaces 101 and 102 whichare generally contoured to engage positively with the anterior surfacesof the adjacent vertebrae. The device has through holes 103 and 104intended to accommodate the insertion of bones screws into the vertebraltissue. Holes 104 may be elongated to accommodate post surgery dynamicsettling of the vertebrae. The device further has one or more holes 105intended for receiving screws (or other fixation devices) securing theretaining member thereto or there-through. The receiving holes 105 alsoprovide a mounting means for the insertion of temporary soft tissueretractor pins. The device has an operating window defined by the sidewalls 106, 107, 108 and 109. This window is intended to allow unimpairedaccess to the intervertebral space in order to excise tissue andsubsequently to allow the insertion of the interbody repair devicethere-through.

FIG. 3 a depicts a multi-level vertebral frame 200, intended tofacilitate the orientation, fixation and repair of three or morevertebrae.

FIG. 3 b depicts a side view of a multilevel device and illustrates thepresence of a receiving means 201 on the vertebral frame, therebypermitting the plate to accommodate the location and retention of softtissue retractor blades.

Referencing FIGS. 4 and 5; the retention member 300 has a posteriorsurface 301 contoured to match the anterior surface of the vertebralframe 200 and through holes 302 which align with the receiving holes 105in the vertebral frame, these holes being intended to secure theretention member 300 to the vertebral frame 200 in order to retain theinterbody implant in position and to prevent the back-out of the bonescrews used to secure frame 200 to the vertebral bone tissue.

FIG. 6 shows retention member 300 installed to the vertebral frame 200,the anterior surface of the retention member having a contour 401 whichgenerally matches that of the vertebral frame 200 to create a smooth,continuous surface after installation.

FIG. 6 further shows the retention member having extensions 420 thatcover the bone screws and thereby preventing screw back-out.

FIG. 7 depicts the vertebral frame in position on adjacent vertebrae andillustrates the operating window in the region of the disk space. Theoperating window is defined by the cross members 503, 504, 505 and 506respectively which produce a contained area through which all proceduresmay be executed. Further, these members act to restrain the surgeonduring tissue excision and thereby minimize the risk of accidentaldamage to surrounding tissue.

FIG. 7 further illustrates how the device provides access to facilitatethe removal of disk material 502 and the preparation of theintervertebral space 501 prior to the insertion of the interbodyimplant.

FIG. 8 is a perspective side view of the vertebral frame in theinstalled position on adjacent vertebrae. The device has clearancespaces 601 in the region of the disk material to accommodate a betterfit to the vertebral surfaces and to provide additional clearance toallow for the removal of unwanted bone material after deviceinstallation.

FIGS. 9 and 10 depict the retention member 300 placed in-situ on thevertebral frame 200 after the insertion of the interbody implant. Themember 300 is located so as to prevent substantial movement of theinterbody implant and thereby promote bone tissue growth therein.

Instead of screws, or in combination therewith, one or more snap lockdevices may be used to attach retention member 300 to vertebral frame200. Such devices may employ a compressible feature, such as a splitbarb, that locks into place when inserted sufficiently into hole 105 orother mating feature. By using snap lock device(s), member 300 can besimply aligned with frame 200 and pressed into place without requiringthe surgeon to align screws and install them with a driver. One or morecam lock devices may also be used, alone or with screws and/or snap lockdevices. In some cam lock embodiments a torsional force is applied to acomponent, inducing rotation and causing it to become engaged in acorresponding feature within a receiving element. This twisting actioncauses the component to turn and lock under another component, againwith less effort than required when installing a screw.

The system offers substantial benefits over those previously disclosedand those currently employed. These benefits include, but are notlimited to:

1) A novel method which allows for precise control and fixation ofoptimal vertebral position.

2) Constrained and controlled tissue removal

3) Elimination of patient to patient variation

4) Integration of soft tissue retraction devices

5) Reduction in surgical time and maneuvers throughout the case.

1. A system for establishing and securing adjacent vertebrae in adefined spacial relationship prior to the excision and repair of damagedtissue, said system comprising: at least one distraction deviceconfigured for temporary placement between adjacent vertebrae andengaging upon opposing inferior and superior end plate surfaces of theadjacent vertebral bodies for achieving a desired spatial relationshipbetween the vertebrae; at least one implantable vertebral frameconfigured to span between the adjacent vertebrae, the frame beingconfigured to attach to each of the adjacent vertebra while thedistraction device is in place to postoperatively maintain the desiredspatial relationship between the vertebrae after the distraction deviceis removed, the frame having at least one internal operating aperturethere-through for providing access to at least one intervertebral diskspace, the aperture sized to fit over the distraction device; at leastone interbody repair implant sized in relationship to the aperture ofthe frame to fit there-through and into the intervertebral space tocompressively engage opposing inferior and superior surfaces of theadjacent vertebral bodies as the implant is being inserted; and at leastone retention member attachable to the frame to cover at least a portionof the aperture.
 2. The system of claim 1, wherein said frame isconfigured to span between and remain postoperatively attached to atleast three adjacent vertebrae.
 3. The system of claim 1, wherein saidframe comprises external walls having integrally manufactured retractorblade engaging features.
 4. The system of claim 1, wherein said framehas a plurality of through holes to facilitate attachment of said frameto adjacent vertebrae by means of bone screws.
 5. The system of claim 1,wherein said frame has a plurality of protrusions thereon to facilitateattachment of said frame to the adjacent vertebrae by means ofimpingement into the bone tissue of the adjacent vertebrae.
 6. Thesystem of claim 1, wherein said frame has one or more receiving elementsto accept a locking member for securing the retention member.
 7. Thesystem of claim 6, wherein said locking member is a threaded screwdevice.
 8. The system of claim 6, wherein the locking member is a snaplock device.
 9. The system of claim 6, wherein the locking member is acam lock device.
 10. The system of claim 6, wherein the one or morereceiving elements for the retention member accommodate the temporarylocation of at least one tissue retractor pin.
 11. The system of claim 1wherein said retention member is configured to retain the interbodyimplant in its surgically established position.
 12. The system of claim1 wherein the frame is configured to receive bone screws there-throughto attach the frame to the vertebrae, the retention member adapted tocover the bone screws when the member is attached to the frame toprevent back-out of said screws.
 13. A method for applying the system inclaim 1, wherein the adjacent vertebrae are distracted and spaciallyoriented with the distraction device, the vertebral frame is secured tothe adjacent vertebrae, the damaged tissue is excised through theoperating aperture in the vertebral frame, the vertebral interspace isprepared to receive the repair implant, said implant being placedthrough the operating aperture into said prepared interspace, and theretention member is then installed onto the vertebral frame.
 14. Amethod for applying the system in claim 1, wherein the vertebral frameis attached to one or more vertebrae, the vertebrae are then distractedand spacially oriented by operating through the operating aperture inthe vertebral frame, the vertebral frame is secured to each adjacentvertebrae, the damaged tissue is excised through the operating aperturein the vertebral frame, the vertebral interspace is prepared through theoperating aperture to receive the repair implant, said interbody implantis inserted through the operating aperture into the prepared interspaceand the retention member is installed onto the vertebral frame.
 15. Thesystem of claim 4 wherein the holes are a combination of elongated slotsand circular holes to accommodate the insertion of bone screwsthere-through into vertebral bone tissue.